1. Field of the Invention
The present invention relates generally to an automated apparatus for handling large numbers of electronic components and more particularly to an apparatus for handling, testing and sorting dual in-line packed (DIP) integrated circuits.
2. Description of the Prior Art
DIP handlers, such as the one of this present invention, are devices for handling great numbers of DIPs in a regular and reliable manner. DIPs can thus be tested, marked and/or sorted in an automated, labor-saving, highly economical fashion.
When the handler is used to test and sort batches of DIPs, it is often desirable to perform these tests at above ambient temperatures. In this way, defects are more readily apparent because the DIP is being tested under simulated operating conditions. For this reason, DIP handlers often have a heated input tray to warm the DIPs to a predetermined temperature.
DIPs usually come in long tubes known as magazines. A magazine is an elongated hollow member having a substantially "A"-shaped saddle running down the center of the magazine. Pins or plugs are provided at either end of the magazine to prevent the DIPs from sliding out.
To be properly handled, it is necessary that the DIPs be discharged into the magazines from the output tray of the handler with the same orientation relative to the magazine that they had when they were discharged from the magazines into the input tray of the handler. In consequence, this means that if a magazine is used to load a number of DIPs into an input tray and a magazine is used to receive a number of tested and sorted DIPs from an output tray, the tested DIPs must be turned around or "reoriented" by the DIP handler somewhere between the input and the output tray. In the prior art this has been accomplished by a reorienter which receives a DIP from a metering device at the discharge end of an input tray and then pivots (usually downwardly) to discharge into the test station.
One problem with the reorienters of the prior art is that the DIPs have to be metered by a discrete device before reorientation can occur. Furthermore, for design considerations, the test head must be placed in an inaccessible position between the input and the output tray, making it difficult to interface the head with a tester.
The input tray of large capacity DIP handlers found in the prior art usually include a number of DIP-guiding tracks. In such systems, each of the tracks has an individual, solenoid-actuated gate which opens to discharge a DIP into a conveyor mechanism which meters and transports the DIPs to the reorienter. Such an arrangement is expensive and unreliable due to the multitude of mechanical or electro-mechanical parts necessary to implement it.
Applicant is aware of the following prior art:
U.S. Pat. No. 3,727,757 to Boissicat;
U.S. Pat. No. 3,655,041 to Baker; and
U.S. Pat. No. 3,198,330 to Weisler.